Study on the coercive force characteristics of AlNiCo magnets and their influence on magnetic circuit design

Coercive force, as an important indicator to measure the ability of magnets to resist external magnetic field interference, is crucial for permanent magnetic materials. The coercive force of AlNiCo magnets is usually low, generally between tens and hundreds of kiloamperes/meter, which is much lower than high-performance permanent magnetic materials such as NdFeB. This characteristic makes AlNiCo magnets easy to lose their original magnetism when facing strong magnetic field interference, thus affecting their stability and reliability.

The reason for the low coercive force is mainly due to the microstructure of AlNiCo magnets. The arrangement of its internal magnetic domains is relatively loose, and the magnetic domain walls are wide, which makes it easy for the magnetic domains to flip under the action of the external magnetic field, thereby losing their original magnetism. The magnetization process of AlNiCo magnets also shows nonlinear characteristics, that is, the relationship between magnetization intensity and magnetic field intensity is not a simple linear relationship, which also increases the risk of losing magnetism under strong magnetic field interference.

Due to the low coercive force, the magnetism of AlNiCo magnets is easily affected when facing strong magnetic field interference. The specific manifestations are:
Decrease in magnetic properties: Under the action of a strong magnetic field, the magnetization intensity of the AlNiCo magnet will decrease rapidly, and may even completely lose its magnetism. This will cause the magnet to fail to work properly, thus affecting the performance of the entire magnetic circuit system.
Changes in magnetic domain structure: Strong magnetic field interference will not only cause the magnetization intensity of the AlNiCo magnet to decrease, but also change its internal magnetic domain structure. This structural change is often irreversible and will cause permanent loss of the magnet's magnetic properties.
Impaired magnetic circuit stability: In the magnetic circuit system, AlNiCo magnets are key components, and the stability of their magnetic properties is crucial to the operation of the entire system. Once the magnet loses its magnetism due to strong magnetic field interference, it will seriously affect the stability and reliability of the magnetic circuit.

In view of the problem of low coercivity of AlNiCo magnets, a series of strategies need to be adopted in the magnetic circuit design to ensure its stability and reliability. Specifically including:
Avoid strong magnetic field interference: In the magnetic circuit design, AlNiCo magnets should be avoided from direct contact with strong magnetic fields as much as possible. The interference of strong magnetic fields on magnets can be reduced by adding shielding layers, adjusting the position of magnets, or changing the direction of magnetic fields.
Optimize magnet shape and size:
The shape and size of magnets have an important influence on their magnetic properties. In magnetic circuit design, the shape and size of magnets should be optimized according to specific application scenarios to improve their anti-demagnetization ability. For example, long cylinders or rod-shaped magnets can be used to reduce the demagnetization area.
Choose a suitable magnetic circuit structure:
The selection of magnetic circuit structure is crucial to the stability and reliability of magnets. In magnetic circuit design, a suitable magnetic circuit structure should be selected according to the magnetic properties of magnets and specific application scenarios. For example, a series or parallel magnetic circuit structure can be used to improve the stability and reliability of the entire magnetic circuit system.
Perform magnetic stabilization treatment:
Magnetic stabilization treatment is an effective way to improve the anti-demagnetization ability of magnets. By applying a certain magnetic field, the magnetic domain structure inside the magnet is made more stable, thereby improving its coercive force. In magnetic circuit design, magnetic stabilization treatment of AlNiCo magnets can be considered to improve their stability and reliability.
Strengthen magnetic circuit monitoring and maintenance:
During the operation of the magnetic circuit, the monitoring and maintenance of magnets and magnetic circuit systems should be strengthened. Once it is found that the magnet loses its magnetism due to interference from a strong magnetic field, timely measures should be taken to repair or replace it to ensure the normal operation of the entire magnetic circuit system.

As an important permanent magnetic material, AlNiCo magnets are widely used in industrial production. However, their relatively low coercivity makes them easy to lose their magnetism when facing strong magnetic field interference, thus affecting the stability and reliability of the magnetic circuit. In the design of the magnetic circuit, it is necessary to fully consider the magnetic properties of the magnet and adopt a series of strategies to deal with the problem of low coercivity. By avoiding strong magnetic field interference, optimizing the shape and size of the magnet, selecting a suitable magnetic circuit structure, performing magnetic stabilization treatment, and strengthening magnetic circuit monitoring and maintenance, the stability and reliability of AlNiCo magnets in the magnetic circuit system can be ensured, providing reference and reference for professionals in related fields.